Hey guys. recently i was given a Sony Vaio VGN-SZ750N that was "bad". turns out, the power supply was shot. easy fix! i ordered a new VGN-AC19V19 off eBay for $14 total. when i received my power supply it was a VGN-AC19V10 instead.

>>Re: Using a power supply a bit bigger then the original? (Laptop power)

The higher Amps rating on the output simply means that it is capable of supplying more current to the computer. In general, this is a good thing as it means the new power supply is more robust than the one it replaces.

As long as the output voltage is the same, it fits where it needs to, and the heat generated and distribution of that heat is similar you'll be fine. However, if they changed the heat sinks to allow more heat to be dissipated by the power supply that does mean it could contribute to over-heating in general, and localized over-heating of adjacent components.

If the power supply is the same form factor, and any heat sinks and shielding look to be the same and in the same places, this likely won't be a problem, but you do have to take into consideration that there is a remote chance that IF the new power supply generates more heat in an enclosed space, it might cause overheating inside the case.

edit to add:
I see McFly posted while I was entering my reply...today's being one of those days...
Another observation about the higher output amps rated unit, is that it also means that for a heavy electrical load, the output voltage(s) will tend to be more stable than the lower-rated unit. Which is also a good thing.

>>Re: Using a power supply a bit bigger then the original? (Laptop power)

No. I am not talking about a desktop power supply. I am talking about a notebook power supply. Even a minor design change such as I described can make a significant difference in how and where the heat is dissipated, especially in the unique configurations found in notebooks. In general, he will likely be ok, but it's something that can't be ruled out entirely.

However, I was talking about the INTERNAL power supply, not an EXTERNAL brick. If you were talking about a brick than the internal design changes of a brick obviously would have no impact on internal notebook case heat distribution.

>>Re: Using a power supply a bit bigger then the original? (Laptop power)

John,

My apologies for assuming. You're clearly a lot more knowledgeable than I when it comes to electricity. I just know that it hurts when I lick it.

It sounded like you were saying that if the PSU generated extra heat, then it would cause the laptop to overheat as well -- which I think is why both Michael and I thought you were referencing a desktop PSU.

>>Re: Using a power supply a bit bigger then the original? (Laptop power)

There are also power supplies inside the notebook. Here's one block diagram. This one shows a laptop that uses an external brick (upper right) to convert the AC mains to a lower DC level which is then input to the various power supply subsections within the notebook http://focus.ti.com/docs/solution/folders/print/342.html to provide power for various parts of the computer.

I was thrown by his use of part numbers in the original post and I over-thought it. I should have asked up front if he was referring to a brick rather than an internal power module.

>>Re: Using a power supply a bit bigger then the original? (Laptop power)

I learned something new, too. Thanks John, nice diagram.

Come to think of it, it's not easy to visualize a laptop has an internal PSU board, in addition to an AC adapter (brick). But for ITX desktop boards, this can be seen obviously. I have a mini-ITX box I built myself, it has a separate 60 Watts PSU circuit board supplying power to the main board via a 20pins connector. It's the same concept for laptops, only the PSU board is on the same board as the main board. In fact, many newer mini-ITX boards are doing the same thing, combining the PSU onto the board, no more 20 / 24 pins power connector.

>>Re: Using a power supply a bit bigger then the original? (Laptop power)

What exactly is the internal "PSU" doing in a laptop?

I had always assumed that the power "brick" on a laptop was "the" PSU, since that's what converts from AC to DC. But only having one output (to the laptop), that differs from a desktop PSU, where most components plug into the PSU.